Lee 2001a.

Study characteristics
Methods	Study design: double‐blind, randomised Country: Taiwan Setting: single centre Intention‐to‐treat: not mentioned
Participants	Number of participants randomly assigned: 50 Number of participants analysed: 50 Exclusions postrandomisation: 0 Losses to follow‐up: 0 Age (mean): cilostazol: 66 (SD 9) years, pentoxifylline: 68 (SD 5) years, placebo: 69 (SD 6) years Sex: male:female: cilostazol: 14/3, pentoxifylline: 14/3, placebo: 14/2 Inclusion criteria: aged > 40 years; stable PAD for ≥ 3 months; baseline maximum walking distance > 30 m and < 200 m; variance < 20% in maximum walking distance in the 2 screening tests Exclusion criteria: Buerger's disease; category II or III chronic lower limb ischaemia; arterial surgery/angioplasty or sympathectomy within previous 3 months
Interventions	Treatment: oral pentoxifylline, 400 mg twice bid Control 1: oral cilostazol, 100 mg bid Control 2: placebo Duration: 8 weeks
Outcomes	Primary: mean TWD Secondary: ABI, side effects
Notes	Treadmill protocol: 3.2 km/h at 12.5% gradient Mean TWD expressed in metres only
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomised code number according to which sponsor supplied the study drug."
Allocation concealment (selection bias)	Low risk	Sealed envelopes.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Special drug packaging was used to maintain the blindness of the treatment code."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No incomplete outcome data.
Selective reporting (reporting bias)	Unclear risk	Protocol not available; insufficient information available to permit judgement.
Other bias	Low risk	Study appeared free of other bias.